陀螺方位角加测数量及位置

Number and position of added measurements of gyroscopic azimuth

港珠澳大桥岛隧工程沉管隧道受沉管隧道长、沉放对接环境复杂、管节沉放水深大、测量控制点不稳定等因素影响,贯通测量精度控制难度非常大。以港珠澳大桥岛隧工程为背景,为了满足沉管隧道贯通测量的高精度要求,采用模拟分析和数学论证的方法,对贯通测量隧道内控制网加测陀螺方位角数量和位置的规律进行分析,得出了加测三条陀螺定向边为宜,且以导线全长均匀布设为最优的结论。

On the island and tunnel project for Hongkong -Zhuhai-Macao Bridge, the immersed tube tunnel is long, theenvironment where immersed tunnel sections are connected is complex, the water depth is great, and the survey control pointsare instable. As a result, it is very difficult to control the accuracy of breakthrough survey. Based on the island and tunnelproject for Hongkong -Zhuhai -Macao Bridge, analyses were made of the pattern of additional gyro -azimuth number andpositions within the control network inside the tunnel when conducting the breakthrough survey by way of simulation analysisand mathematical demonstration in order to meet the high accuracy requirements for the breakthrough survey of the immersedtunnel. The results of the analyses show that it is appropriate to measure three additional gyroscopic directed edges and it isoptimal to evenly lay out the survey transverse along its full length.